MP4.2+6.0

"By the ears" D3 evaluation: Original CD in D3 player with Bose sound in D3 W12. Acoustic glass and lower revs/quiet with W12 gearing. 320kbps AAC bit rate first generation recording of personal CD collection saved vis iTunes and loaded onto iPod with AMI cable. Same source from iPod via Audi sold for a millisecond blue tooth dongle plugged into AMI head (I have one). CD > AMI cable >> bluetooth. BTDT testing all of them, literally with same tracks played back to back. Qualitatively, the AMI hard cable connection at the high bit rate is very close to the CD, but the bluetooth connection has more obvious faults. This is also bluetooth with underlying high bit rate source; if streamed via cellular or a freebie/cheap plan, then the doubled hit of bluetooth and mediocre bit rate. Bluetooth with high bit rate source seems somewhere in same zone as Sirius--which most pretty easily hear the compression on. Again with Sirius on same tracks, when I look a known track up via AMI after hearing it on SAT.

FWIW, on D4 S8 with B&O, same order but the bluetooth rendering is somewhat better. So is Sirius. S8 also has acoustic glass, and yet more sound insulation at margin than D3's. Also geared yet higher by now 8th speed. B&O was also designed from day 1 into D4s, rather than mid life intro w/ D3. Also same as my experience and memory when they gave me a 2011 D4 4.2 loaner for a week with std. Bose and no acoustic glass. One thing I have never done on D4 or Q5 is use the SD slots as a music player source. Those supposedly eliminate one level of conversion found in all the AMI connections, but then the UI and general ease of use apparently goes down relative to AMI with cabled player. Bluetooth player attach also leaves interface more clumsy in general than AMI from my own experience on any of D3, D4 or Q5--even with the factory bluetooth add on device for D3. I suspect many use the player screen in practice for a lot of the UI, which is a hands free no no in a lot of places.

From seeing probably hundreds of posts over the years, what I tend to see as the biggest hit that folks may not realize is the low bit rate recording. Even up to 192kbps I can hear the delta; at 256-320 it gets hard. It is hard to set it up on a D3, but for newer Q5 or D4 era a lot of the use cases are probably using bluetooth to a phone in pocket player as the most obvious hit. Average post seems to use umpteenth generation hand me down files sometimes stored and carried forward for ten years in some cases from like iPhone 1's or whatever, no cognizance of bit rate, very seldom any direct linkage back to the CD (or originally purchased source equivalent). Typical modest bit rate of a lot of the streaming is sort of the newest degrader now taking over a lot of the player market.

mixja23

Pretty much to the untrained ear, unless it's distorting or very flat across the tops, the difference is negligible... And you'd probably only notice it in the way that you have outlined, by comparing them next to each other...
In and ideal world, I'd love to have all my music in WAV form ie: uncompressed and CD quality but seeing as I have around 35,000 songs taking up around 350GB on my hard drive and 200GB on my iPhone respectively (Apple's compression crunches it down even further), I'd need about 4TB just for music...!! And having the choice of either bluetoothing my phone where I can either listen to all of my entire music collection as stored on it or have the option to use streaming apps such as Mixcloud or DI etc, I'll take the further negligible difference against having the phone hard wired in the glove box...
I also use Waze app whilst driving for speed trap alerts, police etc so the phone is stuck to the window anyways for almost all journeys...
It's a convenience thing at the end of the day, the reduction of quality is certainly not enough these days to warrant having a dedicated WAV server or sorts hard wired into the car...
I'm also a DJ and I unashamedly rip a lot of music off of YouTube and I can honestly say again, listening to it on a big system, if you didn't have the original WAV file or vinyl to compare them side by side, it would be hard to spot the difference...
I'm also at the disadvantage at the minute in the S8 as both front speakers are still flapping in the wind and the rears aren't far behind so as such, until I install the replacements (of which I got the whole set of door speakers front and back and the 2 rear shelf speakers for $200!!) I'm listening to only the rear speakers having faded the fronts off completely... I can't help but wonder what a fully functioning B&O system will sound like as I haven't heard one yet...!!!

ltooz_a6_a8_q7

I think 320kbs is overkill IMHO. My MP3 @160kbs sounds perfectly for my ears.
All amplified signals have noise, all band pass filters have noise even the $8k B&O. All music instruments have distortions especially conventional non digital.

Cheers,
Louis

mixja23

Perfectly acceptable these days, even in my crappy old company Nissan Navaro, the sound system was well alright, more than acceptable...
Car audio has come a long way since tape decks and 3" speakers...!!

Greg5OH

you got some deaf ears then lol.
160 sounds like someone playing through a mud puddle, same with 192. mids are blurred, bass is fuzzy, highs are missing.
This is especially prevelant at higher volumes or large speakers. harder to tell on little earbuds but when listening on larger 10-15" high quality speakers and amps, the difference is tremendous.
I refuse to have any 192 kbps in my collection. just hurts the song.